Google maps out flu activity in Mexico

Over the past couple of years, those very clever people at Google.org have been trying to build early-warning systems for diseases - by tracking trends in the data that Google sees in order to build up a picture of whether people are succumbing to certain symptoms.

Engineers admit that it's not perfect, but they do think there's something to be learned from the information:

We cannot be fully confident that the data is correct because we don't have enough historical surveillance data for Mexico against which to compare and calibrate our estimates. Although we cannot validate our estimates as we did for Flu Trends for U.S., we have seen that Google users in Mexico also search for flu-related topics when they experience flu-related symptoms. We are cautiously optimistic that the graphs reflect actual flu activity. The system detected an increase in Mexico City before major news coverage.

Google flu trends for Mexico

Compared to historical data it doesn't look like today's problem is that widespread - because, of course, the data is not weighted towards more virulent strains of the flu virus. But you can see that searches for flu-related topics are higher in the federal district of Mexico and the nearby state of Morelos than in the surrounding countryside.

Now, the crucial thing will be not just to use this to analyse things when a disease is already spreading... but to be able to spot problems before they start to take hold. And that's what researchers such as Nathan Wolfe and the Global Viral Forecasting Initiative are concentrating on.